Screw-propeller.



J. P. AGAN.

SCREW PROPELLER.

APPLICATION IILED JULY 25, 1913.

Patented Sept. 15,1911.

INVENTOR.

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A TTORNE i.

THE NORRIS PETERS 60-. PHOTO L|THO.. WASHINGTON. D. C.

ling efficiency and JOHN P. AG-AN, OF LOUISVILLE, KEIITUGKY, ASSIGNUE 0FSHUMATE AND ONE-THIRD T0 FREDERICK J. LERCH,

TUGKY.

ONE-THIBD TO WILLIAM A. BOTH OE LOUISVILLE, KEN- scnnw-rnornttnn.

Specification of Letters Patent. 1 Application filed July 25, 1913.

Patented Sent. 15, 11.914. Serial No. verses.

To all whom it may concern:

Be it known that I, ,JoHNP. AoAn, a citizen of the United'States,residing at 2620 High street, in the city of Louisville, county ofJefierson, and State of Kentucky, have invented a newand usefulImprovement in Screw-Propellers, of which the following is aspecificatio This invention relates to screw propellers.

The screw propeller owes its propulsive effect to the reaction of thebody of fluid it forces rearwardly in lines parallel with its axis. Suchpart of the media, in which the propeller rotates, as is thrown off inlines tangent to the axis is non-effective.

An object of this invention is to provide an improved propeller for useon various class of craft which shall be of simple construction,efi'icient in operation and possess marked advantages hereinaftermentioned.

Another object is to increase the propeldecrease the vibration generallycaused by propellers of the usual construction.

The propeller of usual construction throws a percentage of the water onwhich it acts at a tangent, this tion so familiar in the driven vessels.

A further object is to provide a construction of propeller that willintercept that portion of the media, in which the propeller is acting,that is thrown 0d at a tangent by'the centrifugal action thereof anddivert it to lines parallel with the axis.

These objects 1" attain by the novel construction set forth, andillustrated in the accompanying drawing which forms a part of thisspecification, in which is set forth an embodiment of in invention, butit is to be understood that changes, variations and modifications may beresorted to that come within the scope of the claims appended hereunto.

in the drawing, in which like reference characters indicate like partsin the several views; Figure 1, is a rear elevation; Fig. 2, a sideelevation; Fig. 8 sections. on the lines o- 21, w re, YY, m-w and ZZ ofFig. 1.

Referring to the drawing -1 denotes the hub, that may be of any formdesired; a/"" denotes the usual opening therewake of propeller causesthe ebullithrong 1 for the shaft, and -3 denotes the blades, which maybe attached tothe hub in any convenient, or desired manner. The arrowlindicates the direction in which the propeller is assumed to turn, 2'.e. to the right, and therefore 5 is the leading edge, and -6- thefollowing edge of the blade. -7- indicates the propelling face of theblade and S- the rear face thereof. The blades may be of a size suitableto the class and size of craft on which they are to be used, and anykind of pitch may he employed-such as a uniform pitch, a simpleincreasing or simple decreasing pitch- 2'. c. increasing or decreasingfrom the leading to the following edge, or progressively increasing ordecreasing pitch, or a 001m pound increasing or decreasing pitch fromthe leading to the following edge and from the hub to the periphery, butfor all ordinary purposes I prefer to employ blades having a uniformpitch as illustrated. The

blade is provided With an incurved tip 9 that extends, with a decreasingpitch, across the blade from the leading edge and merges in thefollowing edge, and is adapted to intercept, and divert rearwardly, inlines parallel with the axis, such of the fluid as may be thrown out inradial lines by the centrifugal action of the blades. The amplitude ofthe tip 9 is greatest at its connection with the leading edge anddecreases until it merges into the following edge. It

is to be understood that the size and pitch of the incurvate tip may bevaried in accordance with the size and pitch of the blades used.

In operation the leading edge cuts the water, or other media, the tip 9intercepts and diverts any radial flow to lines parallel with the axis.An effect of the divergent streams of fluid impinging on the incurvatetips is to balance and steady the propeller, in a large measure reducingthe vibrations incident to the use of the usual propeller, thus givingan easier riding boat.

That considerably better results are obtained by the use of a propellerprovided with an incurvated tip in accordance with my invention, thanwith a propeller not so provided is clearly shown by extensive practicalexperiments I have made. The experiments show that a propellerconstructed' according to my invention gives a the usual propellerhavand that With a propeller having the tip incurvedaccording to myinvention the same speed may be attained With a less number ofrevolutions than With a propeller of the usual construction.

Having thus described my invention so that any one skilled in the artpertaining thereto may make and use the same, I

. claim 1. A propeller comprising a hub and a blade, said blade havingan incurvate tip extending, with a diminishing pitch, across the end ofthe blade.

2. A propeller comprising a hub and pin rality of blades pitched attransverse 111- clinations on lines oblique to the axial line of saidhub, and having 'incurvate tips extending with a diminishing pitchacross the ends of said blades presenting portions adapted to dischargerearwardly therefrom.

JOHN P. 'AGAN.

Witnesses: a

W. B. MUNNELL, F. H. KAPPA.

Copies of this patent may be obtained for five cents eac11, byaddressing Washington, I C.

the I Commissioner of IEatents.

